Slender women worry about packing on extra weight, say Brigham Young University researchers who used MRI technology to observe what happened in the brain when people viewed images of complete strangers.

If the stranger happened to be overweight and female, it surprisingly activated an area in women's brains that processes identity and self-reflection. Men did not show signs of any self-reflection in similar situations.

"These women have no history of eating disorders and project an attitude that they don't care about body image," said Mark Allen, a BYU neuroscientist. "Yet under the surface is an anxiety about getting fat and the centrality of body image to self."

The results appear in Personality and Individual Differences.

When anorexic and bulimic women view an overweight stranger, the brain's self-reflection center – known as the medial prefrontal cortex – lights up in ways that suggest extreme unhappiness and in some cases, self-loathing.

The motivation for this new study was to establish a point of reference among a control group of women who scored in the healthy range on eating disorder diagnostic tests. Surprisingly, even this control group exhibited what the authors call "sub-clinical" issues with body image.

"Although these women's brain activity doesn't look like full-blown eating disorders, they are much closer to it than men are," Allen said.

The authors note that women are bombarded with messages that perpetuate the thin ideal, and the barrage changes how they view themselves.

"Many women learn that bodily appearance and thinness constitute what is important about them, and their brain responding reflects that," Spangler said. "I think it is an unfortunate and false idea to learn about oneself and does put one at greater risk for eating and mood disorders."

I agree, it's time to stop worrying about the 5 skinny chicks left in America. We are simultaneously told oppressive male-dominated American culture applies too much pressure to be thin yet we are the fattest people on the planet.

Facts and unbiased observations don't seem to matter much to the people who do some of the soft science studies. It just struck me that, we are now so worried about offending fat people that being thin (normal weight) is now a disease. If a woman is thin she is playing to that "male dominated society". :-/

I don't think this is any kind of indictment on people who are able to keep themselves at a healthy weight. Really it seems to be showing that the socialization is affecting the thoughts of women, even those who aren't pathological.

As for obesity and over-done messages of a thin ideal, they obviously aren't mutually exclusive. The obesity problem likely stems from many sources (changes in exercise patterns, availability of food to modern people, reliance on fast-food, etc) while problems with self image stem from cultural and media messages. The messages about thin image in media result can still cause psychological pain to women (or men) of all body types. What we're seeing now is that the changes in though are appearing at the deep brain level.